Saad logged an assist, three shots on goal and two blocked shots in Saturday's 4-3 win over the Bruins.
Saad inked a one-year contract with Vegas on Friday.
Saad was placed on unconditional waiver by the Blues on Wednesday for the purpose of terminating his contract.
Saad was placed on waivers Tuesday, Jeremy Rutherford of The Athletic reports.
Saad scored two goals on four shots in Thursday's 4-3 overtime loss to Buffalo.
Saad notched an assist and two shots on goal in Tuesday's 3-2 win over the Lightning.
Saad scored two goals in Tuesday's 3-2 loss to the Jets.
Saad (personal) was activated from the non-roster list Monday, per the NHL media site.
Saad is back in St. Louis for the birth of his child and was placed on non-roster injured reserve Monday.
Saad garnered an assist in Sunday's 4-1 victory against the Kraken.